/Engine/Source/Runtime/NavigationSystem/Public/NavigationOctree.h
Retrieves Modifier, if it doesn't contain any "Meta Navigation Areas". If it does then retrieves a copy with meta areas substituted with appropriate non-meta areas, depending on NavAgent
[FCompositeNavModifier](API\Runtime\Engine\AI\FCompositeNavModifier) GetModifierForAgent ( const struct [FNavAgentProperties](API\Runtime\Engine\AI\Navigation\FNavAgentProperties) * NavAgent ) const